Mammals harbor diverse microbial species in their gastrointestinal (GI) tracts. Interactions between these microbes and between microbes and the host, e.g. the host immune system, shape a microbiota. A healthy microbiota provides the host with multiple benefits, including colonization resistance to a broad spectrum of pathogens, essential nutrient biosynthesis and absorption, and immune stimulation that maintains a healthy gut epithelium and an appropriately controlled systemic immunity. An unbalanced microbiota (also called ‘dysbiosis’ or disrupted symbiosis) may lose its function and results in increased susceptibility to pathogens, altered metabolic profiles, or induction of proinflammatory signals that can lead to local or systemic inflammation or autoimmunity. Additionally, such a disrupted microbiota may be infected by incoming pathogen or pathogens, which can cause pain, diarrhea, gas, and constipation among other symptoms. Hence, the intestinal microbiota plays a significant role in the pathogenesis of many disorders such as pathogenic infections of the gut.
Implantation or administration of human colonic microbiota into the bowel of a sick patient is called Fecal Microbiota Transplantation (FMT), also commonly known as fecal bacteriotherapy. FMT is believed to repopulate the gut with a diverse array of microbes that control key pathogens by creating an ecological environment inimical to their proliferation and survival. It represents a therapeutic protocol that allows a fast reconstitution of a normal compositional and functional gut microbial community.
FMT has been used to treat Clostridium difficile infection (CDI). FMT has also been suggested in treating other gut infective agents such as E. coli and Vancomycin resistant Enterococci (VRE). It entails infusions through a colonoscope, an enema or via a nasojejunal tube of human microbiota either in the form of homogenised stool, or cultured stool components such as Clostridia, to implant in the colon and thereby displace or eradicate pathogenic bacteria, e.g., C. difficile. 
Without being bound to any theory, multiple sclerosis (MS) is considered by some as a disabling autoimmune disease of the central nervous system. In multiple sclerosis the immune system attacks the protective myelin sheath of nerve fibers. Damage to the myelin sheath slows down or stops nerve signaling and causes miscommunication between the brain and spinal cord and other parts of the body. The disease can progress to permanent damage of the nerves. Multiple sclerosis consists of four disease types, including clinically isolated syndrome (CIS), relapsing-remitting multiple sclerosis (RRMS), primary progressive multiple sclerosis (PPMS), and secondary progressive multiple sclerosis (SPMS). Symptoms of multiple sclerosis vary depending on the amount of nerve damage, location of damage and severity of the disease. Attacks can last for days, weeks, or months, followed by periods of remission. People who suffer from severe multiple sclerosis may lose the ability to walk. Other symptoms can include loss of balance, muscle spasms, numbness, motor difficulties, tremors and limb weakness. Additional symptoms can affect the bowel or bladder. These include constipation and stool leakage, difficulty urinating, frequent urination, and urine leakage. A subject with multiple sclerosis can also suffer from double vision, eye discomfort, rapid eye movements and vision loss. Multiple sclerosis may further cause memory loss, difficulty solving problems, depression, hearing loss, slurred speech and difficulty with chewing and swallowing.
Existing treatments for multiple sclerosis involve medication that can decrease or diminish symptoms and slow down the disease. Multiple sclerosis affects women more than men and is most commonly diagnosed between ages 20 to 40. The hospitalization rates of multiple sclerosis patients decreased by 75% in 2011, in comparison to 1984, however, hospitalization rates of multiple sclerosis patients remain higher than hospitalization rates of the general population. See, Marrie et al., Neurology 2014; 83: 929-937. Thus, there is a need for more effective treatments for multiple sclerosis that are easier to administer.